Hi everyone, ive been a long time lurker and stealer of information off the site for working on my car, without issue… now I need to post!

I have just finished fixing the valley pan, O-rings… the general coolant overhaul that every E39 M62 owner has to do. Today I got it back together and went to turn the key, flat battery.. so I gave it some charge and turned the key. Its turning over but won’t start, when I got out of the car after fighting with it for 5 mins to get it to start, I had a good haze of smoke… when it was turning over I heard a few pops. Im struggling to understand why it won’t start.

Note, I was using the service key (it shouldn’t matter if im not using the main key? The battery in it is flat)

My first thought was that I’ve put a connection in the wrong spot but everything seems correct, is there anywhere where I can get a look at a diagram for where all of the plugs go off the loom?